JP2010097786A - Circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker which does not exhaust arc gas to the outside of an arc cover by installing the arc cover for taking in the arc gas exhausted from a circuit breaker at the outside of the case. <P>SOLUTION: The circuit breaker 1 is provided with a case 10, a pair of terminals (load side terminal 20 and power supply side terminal 30) supported by the case 10, a fixed contact 50 which is arranged in the middle of a load current route connecting the pair of terminals, a movable contact 40 which is arranged in the middle of the load current route and switches over switch-on and breaking of the load current by contacting and separating from the fixed contact 50, an arc gas exhaust hole 12 which is formed in the vicinity of the fixed contact 50 in the case 10 and discharges to the outside of the case 10 an arc gas G generated when the movable contact 40 contacts or separates from the fixed contact 50, and an arc cover 200 which is installed at the outside of the case 10 so as to surround the arc gas exhaust hole 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a circuit breaker that forcibly breaks a circuit when an overcurrent flows in an electric circuit.

  Conventionally, in a circuit breaker, a terminal cover that covers the terminal part is used to prevent an electric shock when a person touches the terminal exposed to the outside of the case or a short circuit due to foreign matter accumulating between adjacent terminals. Some are provided. In addition, in a circuit breaker in which arc gas is generated when the circuit is interrupted (for example, when the movable contact is moved away from the fixed contact), a technique for providing an exhaust port for discharging the arc gas to the outside is disclosed. (For example, refer to Patent Document 1 and Patent Document 2).

  For example, as shown in FIG. 11, the arc gas G generated in the circuit breaker body 700 travels in the direction of the terminal 710 (in the direction of the arrow) and is discharged to the outside from the exhaust port 702 provided in the circuit breaker body 700. Is done. Further, a cover side exhaust port 722 is provided in the terminal cover 720 provided so as to cover the terminal 710 in order to prevent the terminal cover 720 from being broken by receiving a large exhaust pressure of the arc gas G. The cover-side exhaust port 722 is composed of a plurality of crosspieces 723 as shown in FIG. The crosspiece 723 includes an upper crosspiece section 723a and a lower crosspiece section 723b, and a notch 723c is provided between the upper crosspiece section 723a and the lower crosspiece section 723b. The crosspiece 723 is configured such that the upper crosspiece section 723a and the lower crosspiece section 723b can bulge outward by the notch portion 723c. Therefore, as shown in FIG. 5B, when the pressure in the terminal cover 720 is increased by the arc gas G, the upper beam portion 723a and the lower beam portion 723b bulge outward, thereby opening the cutout portion. The arc gas G is exhausted from 723c to lower the pressure (see Patent Document 1).

  FIGS. 13A and 13B are electromagnetic contactors in which a terminal cover 820 is provided in the arc box 800. The terminal cover 820 has a rotatable front door 822, and by rotating the front door 822, the opening hole 823 is opened, and the arc gas exhausted from the arc gas blowing hole 802 is discharged to the outside of the terminal cover 820. (See Patent Document 2).

Furthermore, as shown in FIG. 14, the circuit breaker 900 including the case 901 and the cover 902 includes a separator 920 so as not to release the arc gas G to the outside (see Patent Document 3).
JP 2002-140972 A JP-A-11-167854 Sho 58-17755

  However, in the inventions disclosed in Patent Documents 1 and 2, arc gas is actively exhausted to the outside from an exhaust port provided in the terminal cover. Therefore, in order to maintain insulation between the arc gas exhausted from the circuit breaker and other devices, a certain gap is required between the exhaust port of the circuit breaker and the other devices. Therefore, there is a waste of space in the vicinity of the exhaust port of the circuit breaker. For example, there is a problem that it becomes a great obstacle to downsizing the switchboard on which the circuit breaker is installed.

  Further, in the invention disclosed in Patent Document 3, the arc gas is trapped in the entire sealed case, and even if the fixed contact and the movable contact are separated in this state, the contact between the contacts is short-circuited by the trapped arc gas. There was a problem that it might end.

  In view of such circumstances, the present invention intends to provide a circuit breaker that does not exhaust arc gas to the outside of the arc cover by providing an arc cover for taking in the arc gas exhausted from the circuit breaker on the outside of the case. Is.

  (1) The present invention is arranged in the middle of the case, the pair of terminals held by the case, the fixed contact arranged in the middle of the load current path connecting the pair of terminals, and the load current path. A movable contact that switches between energization and interruption of a load current in contact with and away from the fixed contact, and the movable contact that is formed in the vicinity of the fixed contact in the case, and the movable contact contacts or separates from the fixed contact A circuit breaker comprising: an arc gas discharge hole for discharging the arc gas generated in the outside to the outside of the case; and an arc cover provided so as to surround the arc gas discharge hole on the outside of the case.

  (2) In the present invention, a case side engaging portion is formed in the case, a cover side engaging portion is formed in the arc cover, and the cover side engaging portion is formed in the case side engaging portion. The circuit breaker according to (1), wherein the arc cover is detachably attached to the case by engaging with each other.

  (3) The circuit breaker according to (2), wherein the cover side engaging portion and the case side engaging portion are engaged by snap fit.

  (4) The present invention is also characterized in that the arc cover includes a contact surface in contact with a surface around the arc gas discharge hole in the case in a surface state. It is a circuit breaker in any one.

  (5) The circuit breaker according to (4), wherein the contact surface is disposed at least between the terminal and the arc gas discharge hole.

  (6) According to the present invention, a holding portion for holding a magnet is formed in the vicinity of the fixed contact in the case, and the magnet is held in the holding portion and is generated by the magnet. The circuit breaker according to any one of (1) to (5), wherein the arc gas is discharged from the arc gas discharge hole by force.

  (7) The case includes at least a case piece that forms an internal space in which the fixed contact and the movable contact are accommodated, and a holding plate that is mounted on an outer wall of the case piece. At least one of the plates is formed with a recess serving as the holding portion for holding the magnet, and the magnet is sandwiched between the case piece and the holding plate while being accommodated in the recess. The circuit breaker according to (6).

  (8) The circuit breaker according to (7), wherein the case side engaging portion is formed on the holding plate side of the case.

  (9) The circuit breaker according to any one of (1) to (8), wherein a plurality of the cases are provided, and at least the fixed contact and the movable contact are accommodated in each case. .

  (10) Each of the plurality of cases includes a case contact surface that engages with the other case, and one case engages with the other case by the case contact surface, The circuit breaker according to (9), wherein a plurality of the cases are connected in parallel.

  (11) The plurality of cases are connected to each other in parallel with the magnet sandwiched therebetween, and the arc gas is discharged from the arc gas discharge hole by Lorentz force generated by the magnet. The circuit breaker according to (9) or (10), wherein

  (12) The circuit breaker according to any one of (9) to (11), wherein the single arc cover simultaneously surrounds the arc discharge holes of the plurality of cases connected in parallel. .

  (13) A shielding plate that further shields the pair of terminals of one case and the pair of terminals of the other case, and the arc cover includes a shielding plate relief into which the shielding plate is inserted. The circuit breaker according to any one of (9) to (12), wherein a section is provided.

  (14) The arc cover includes a blocking wall therein, and the blocking wall is positioned between the arc gas discharge hole of one of the cases connected in parallel and the arc gas discharge hole of the other case. The circuit shield according to any one of (9) to (13).

  (15) The arc cover is a substantially hexahedron member that is partially open and has an internal space, and the internal space of the arc cover communicates with the arc gas discharge hole in the case through the opening. The circuit breaker according to any one of (1) to (14), wherein the circuit breaker is provided as described above.

  (16) The arc cover includes a ceiling portion facing the arc gas discharge hole in the case, a terminal portion standing on the ceiling portion and disposed between the arc gas discharge hole and the terminal, The circuit breaker according to (15), further comprising an anti-terminal portion facing the terminal portion and a pair of side portions corresponding to the outer side surface of the case.

  (17) The opening edge of the terminal portion is provided with a buffer piece protruding in the direction of the opening surface, and the surface of the buffer piece facing the case is located between the arc gas discharge hole and the terminal in the case. The circuit breaker according to (16), wherein a contact surface is further provided at a position where the contact circuit is in contact with the circuit breaker.

  (18) The pair of side portions of the arc cover is provided with a cover-side extension portion that extends as it is from the opening end face of the internal space to the outer surface side of the case, and the cover-side extension portion is formed of the case The circuit breaker according to (16) or (17), characterized in that an outer surface of the circuit is engaged.

  According to the present invention, by providing an arc cover for taking in the arc gas exhausted from the circuit breaker outside the case, it is possible to provide a circuit breaker that does not exhaust the arc gas outside the arc cover. obtain.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  <Internal structure of circuit breaker>

  FIG. 1 is a cross-sectional view showing the internal structure of the circuit breaker 1 showing a state where the movable contact and the fixed contact are separated (breaking state).

  The circuit breaker 1 includes a case 10, a load side terminal 20, a power source side terminal 30, a movable contact 40, a fixed contact 50, a frame 60, a handle 70, a movable link 80, and a holding plate 120 (details). And an arc cover 200 (details will be described later).

  The case 10 is a substantially box-shaped member molded from a resin having heat resistance and fire resistance. The case 10 has an internal space, and a load side terminal 20, a power source side terminal 30, a movable contact 40, a fixed contact 50, a frame 60, a handle 70, a movable link 80, and the like are accommodated at predetermined positions in the internal space. Yes. Further, the case 10 has an arc discharge hole 12 formed in the vicinity of the fixed contact 50, and an arc cover 200 is assembled outside the arc discharge hole 12 so as to surround the arc discharge hole 12.

  As shown in FIG. 3, the case 10 is configured by combining two case pieces 10a so as to face each other. Each case piece 10 is formed with an arc discharge notch 12a. Accordingly, by combining the case pieces 10a, the arc discharge holes 12 are formed from the pair of arc discharge cutouts 12a and 12a.

  Further, the arc discharge notch 12a includes a rectangular discharge notch 13a and a T-shaped discharge notch 14a. The T-shaped discharge notch 14a is formed at a position closer to the fixed contact 50 than the rectangular discharge notch 13a, and is formed to extend to the vicinity of the rectangular discharge notch 13a. By combining the two case pieces 10 face to face, the rectangular discharge holes 13 are formed from the rectangular discharge notches 13a formed in the respective case pieces 10a, and the T-shaped discharge holes 14 are formed from the T-shaped discharge notches 14a. Is formed.

  Returning to FIG. 1, the load-side terminal 20 is a sheet metal member formed of a conductive metal. The load side terminal 20 is connected to one end of the conductive cable 90 by solder or the like. The other end of the conductive cable 90 is connected to the frame 60 by solder or the like. Therefore, the load side terminal 20 is electrically connected to the frame 60 via the conductive cable 90.

  Further, the load side terminal 20 is formed with an opening 22 for fixing a load side cable (not shown) connected to a device (hereinafter referred to as a load) that consumes power. A screw portion 22 a is formed in the back of the approximate center of the opening 22. By screwing a fixing screw (not shown) into the screw portion 22a, the load side cable is fixed to the load side terminal 20 using the fixing screw.

  The power supply side terminal 30 is a sheet metal member formed of a conductive metal. The power supply side terminal 30 is connected to the fixed contact 50, and the power supply side terminal 30 and the fixed contact 50 are electrically connected.

  Further, the power supply side terminal 30 has an opening 32 for fixing to a power supply side cable (not shown) supplied from the power supply. A screw portion 32 a is formed in the back of the substantially center of the opening 32. By screwing a fixing screw (not shown) into the screw portion 32a, the power-side cable is fixed to the power-side terminal 30 using the fixing screw.

  The movable contact 40 is supported on the frame 60 by a fixed support shaft 62. The movable contact 40 is configured to be swingable with respect to the frame 60 about the fixed support shaft 62 as a rotation axis. Although details will be described later, the movable contact 40 is pivotally supported on the link frame 82 by the second movable shaft 84. The operation of the handle 70 is transmitted to the movable contact 40 by the movable link 80 including the link frame 82 and the second movable shaft 84, and the direction close to the fixed contact 50 (arrow A direction) or from the fixed contact 50. It can be swung in a direction away (arrow B direction).

  The fixed support shaft 62 is provided with a spring 95, and the movable contact 40 always receives a force pushed up in a direction away from the fixed contact 50 (direction of the frame 60).

  The handle 70 has an operation side end 72 formed on one end side and a link side end 74 formed on the other end side. The operation side end 72 is subjected to shot blasting or concavo-convex forming so that a person can easily operate the handle 70 with a finger. Further, the link side end 74 has a substantially disk shape, and a rotation shaft 75 is provided at the center. The rotating shaft 75 supports the handle 70 so as to be swingable with respect to the frame 60.

  A first movable shaft 83 of the movable link 80 is connected to the circumference of the link side end 74. Therefore, the first movable shaft 83 itself connected to the link side end 74 is caused by the handle 70 swinging clockwise (arrow C direction) or counterclockwise (arrow D direction) about the rotation shaft 75. Moves clockwise or counterclockwise. When the first movable shaft 83 moves clockwise, the link frame 82 rotates in the direction opposite to the handle 70 around the first movable shaft 83 while being pushed toward the movable contact 40 side. Thereby, the movable contact 40 can swing in the direction of the fixed contact 50 (the direction of the arrow A or the direction of the arrow B) with respect to the pushing force of the spring 95 in the direction of the frame 60 (details will be described later).

  The movable link 80 constitutes a link mechanism by the link frame 82, the first movable shaft 83, the second movable shaft 84, the frame 60, and the handle 70.

  Note that the contact and separation of the movable contact 40 with respect to the fixed contact 50 are not limited to those in which the movable link 80 is operated by operating the handle 70 as described above and the movable contact 40 is moved. It is also preferable that the movable contact 40 is moved by pressing the push button in the push switch.

  <Switching operation with movable contacts>

  Next, the switching operation of the movable contact will be described with reference to FIGS. FIG. 2 is a cross-sectional view showing the internal structure of the circuit breaker 1 in a state where the movable contact is in contact with the fixed contact (energized state).

  First, as shown in FIG. 1, the handle 70 is swung clockwise (in the direction of arrow C) when the circuit breaker 1 is in a disconnected state (a state where the movable contact 40 is separated from the fixed contact 50).

  As the handle 70 swings clockwise, the link-side end 74 of the handle 70 and the first movable shaft 83 connected thereto swings clockwise about the rotation shaft 75.

  The first movable shaft 83 connected to the link side end 74 moves in the direction of the movable contact 40 and toward the frame 60 by the clockwise swing. The link frame 82 swings counterclockwise about the first rotation shaft 83 while being pushed toward the movable contact 40 side.

  Further, the force for moving the link frame 82 toward the movable contact 40 is transmitted to the movable contact 40 via the second movable shaft 84. Since the movable contact 40 is swingably supported by the frame 60 by the fixed support shaft 62, the movable contact 40 rotates in the A direction about the fixed support shaft 62. As described above, the fixed support shaft 62 is provided with the spring 95. Therefore, the movable contact 40 is pressed against the fixed contact 50 by the load of the spring 95 to obtain stable conduction.

  On the other hand, when the handle 70 is rotated counterclockwise (in the direction of arrow D) in the state of FIG. 2, the link side end 74 of the handle 70 and the first movable shaft 83 rotate and move counterclockwise.

  Thereby, the 1st movable shaft 83 moves in the direction away from the movable contact 40, and the link frame 82 connected with the 1st movable shaft 83 also moves similarly. As a result, the link frame 82 swings clockwise about the first movable shaft 83. Therefore, the movable contact 40 connected to the link frame 82 is pulled away from the fixed contact 50, and at the same time, the spring 95 provided on the fixed support shaft 62 is forced to open counterclockwise. In addition, it swings instantaneously in the counterclockwise direction (arrow B direction) around the fixed support shaft 62.

  With the above configuration, the movable contact 40 moves in accordance with the operation of the handle 70 so as to be in contact with or disconnected from the fixed contact 50.

  <Arc gas discharge method>

  Next, the discharge method of arc gas is demonstrated using FIG.

  A magnet 100 is provided in the vicinity of the fixed contact 50 on the outer surface of the case piece 10a. The magnet 100 is arranged so that the front side of the paper surface of the one case piece 10a is an N pole, and is opposed to a magnet (not shown) provided on the other case piece (not shown) assembled so as to face each other. It arrange | positions so that the surface to do may become a south pole. Therefore, the magnetic force by the magnet 100 is generated from the N pole side toward the S pole side (in the direction of arrow J).

  On the other hand, a positive electrode is connected to the power supply side terminal 30 of the fixed contact 50, and a negative electrode is connected to the load side terminal 20 of the movable contact 40. Therefore, the load current flows from the fixed contact 50 side toward the movable contact 40 (in the direction of the arrow K).

  Accordingly, the Lorentz force R is generated from the fixed contact 50 toward the arc gas discharge hole 12 in accordance with Fleming's left-hand rule. The arc gas G is discharged from the arc gas discharge hole 12 to the outside of the case 10 by the Lorentz force R.

  The discharged arc gas G is taken into an arc cover 200 (details will be described later) assembled so as to surround the arc gas discharge hole 12 outside the case 10, and is gradually cooled and disappears by touching air inside. To do.

  <Case structure>

  Next, the structure and the like of the case 10 of the circuit breaker 1 will be described with reference to FIG. The figure is an exploded view of the case 10 as seen from the arc gas discharge hole side with the arc cover removed.

  The case 10 includes a pair of case pieces 10a and 10a, and a pair of holding plates 120 and 120 disposed on the outside of the case piece 10a.

  Further, the case 10 is provided with a flat surface 16 (shaded area in the figure) extending from the outer edge of the T-shaped discharge hole 14 toward the power supply side terminal 30, and a contact surface 208 (details will be described later) of the arc cover 200. It can come into contact with the surface.

  In the vicinity of the fixed contact 50 (see FIGS. 1 and 2), a holding recess 17 that does not penetrate to the inside is formed on the outer surface of the case piece 10a, and the magnet 100 can be engaged with the holding recess 17. Yes.

  The holding plate 120 is a substantially plate-shaped member made of resin. The holding plate 120 engages with the side surface 18 of the case piece 10 a and is fixed to the case piece 10 a by the rivet 140 from the outside of the holding plate 120. The holding plate 120 is formed with a recess 122 for accommodating the magnet 100. When the holding plate 120 is engaged with the case piece 10a, the holding plate 120 side recess 122 and the case piece 10a side holding recess 17 The magnet 100 can be accommodated while being held.

  Further, in the present embodiment, the holding recess 17 formed on the side surface 18 of the case piece 10a does not penetrate to the inside of the case piece 10a, and can be accommodated by about half the thickness of the magnet 100. In addition, the concave portion 122 of the holding plate 120 can be accommodated by the thickness of about half of the magnet. Therefore, the thickness of the case piece 10a can be equal to or less than the thickness of the magnet 100, the thickness of the member can be reduced, and the case 10 as a whole can be downsized.

  Needless to say, at least one of the holding concave portion 17 and the concave portion 122 may be provided.

  Further, an engaging convex portion 124 is provided on the outer surface 126 of the holding plate 120 so that it can engage with an engaging concave portion 206 (details will be described later) of the arc cover 200.

  <Arc cover>

  Next, the arc cover 200 according to the first embodiment will be described with reference to FIGS. 6 and 7.

  6A is a front view of the arc cover 200 according to the first embodiment, FIG. 6B is a right side view of the arc cover 200, and FIG. 6C is the arc cover. 200 is a left side view of the arc cover 200, FIG. 6D is a bottom view of the arc cover 200, and FIG. 9E is a plan view of the arc cover 200. 7A is a cross-sectional view seen from the direction of arrows PP in FIG. 6C, and FIG. 7B is a diagram seen from the directions of arrows QQ in FIG. 6C. FIG.

  The arc cover 200 is a substantially hexahedral member formed of resin. The arc cover 200 is open on one side (in this embodiment, the bottom surface), and the inside of the hexahedron is an internal space (hereinafter referred to as an arc housing portion 202) (see FIG. 7).

  Specifically, the arc cover 200 is a ceiling portion 200 a facing the arc gas discharge hole 12 of the case 10, and a terminal that is erected with respect to the ceiling portion 200 a and isolates the arc discharge hole 12 from the power supply side terminal 30. A portion 200b, a terminal portion 200c opposite to the terminal portion 200b, and a pair of side portions 200d corresponding to the outer surface 126 of the case 10.

  Further, on both side surfaces 200d in the longitudinal direction of the arc cover 200 having a substantially hexahedron that is open on one side, cover side extended portions 204 that extend from the opening end surface of the arc housing portion 202 to the outer surface 126 side of the case 10 are formed. Yes. Two cover recesses 206 are formed at positions corresponding to the engagement protrusions 124 of the holding plate 120 in the two cover side expansion portions 204, 204. As a result, the arc cover 200 can be engaged with the holding plate 120.

  The cover side extended portion 204 is in close contact with the outer surface 126 of the holding plate 120. Thus, since the arc cover 200 is engaged so as to hold the outer surface 126 of the case 10 including the holding plate 120, it is possible to reliably prevent the arc gas from leaking from both sides of the arc cover 200.

  Moreover, since the terminal part 200b of the arc cover 200 is disposed between the arc gas discharge hole 12 and the power supply side terminal 30, it is possible to prevent the arc gas G released to the arc accommodating part 202 from leaking in the direction of the power supply side terminal 30. . In particular, a buffer piece 200e projecting vertically outward is formed at the opening edge of the terminal portion 200b, and an abutting surface 208 is further formed on the lower surface (the surface facing the case 10) of the buffer piece 200e. When the arc cover 200 is engaged with the holding plate 120, the abutting surface 208 is configured to be in close contact with the flat surface 16 provided from the arc gas discharge hole 12 to the power supply side terminal 30 in the case 10. . Thereby, the leakage of the arc gas G to the terminal side can be reduced more effectively.

  Needless to say, the contact surface 208 is not limited to the shape of the present embodiment. That is, when the arc cover 200 is engaged with the case 10, it is preferable that a part of the arc cover 200 and the plane 16 existing between the arc gas discharge hole 12 and the power supply side terminal 30 in the case 10 are in contact with each other. . For example, it may be realized by making the resin of the terminal portion 200b of the arc cover 200 thick.

  Next, the case where the arc cover 200 is assembled to the case 10 will be described. FIG. 8A is a front view of the circuit breaker 1 immediately before the arc cover 200 is assembled to the case 10, and FIG. 8B is a side view of the circuit breaker 1.

  The engagement concave portion 206 of the arc cover 200 is engaged with the engagement convex portion 124 of the holding plate 120, and as a result, the arc cover 200 can be engaged with the holding plate 120. When the engaging convex part 124 fits into the engaging concave part 206, the cover side extended part 204 of the arc cover 200 is temporarily elastically deformed and integrated with a “click” by a so-called snap-fit structure. .

  Note that the interval L between the two cover side expansion portions 204 of the arc cover 200 is set to be the same as the interval M between the side surfaces 126 of the case 10, but the interval L is slightly narrower than the interval M (L <M). Even preferred. The arc cover 200 may be fixed to the case 10 with a stronger snap-fit structure by making the interval L between the case-side engagement pieces 204 smaller than the interval M between the side surfaces 126.

  Further, when the arc cover 200 is engaged with the case 10, the cover side extended portion 204 and the contact surface 208 of the arc cover 200 are in close contact with the outer surface 126 and the flat surface 16 of the case 10 in a surface state, respectively. Therefore, it is possible to prevent the arc gas discharged from the arc gas discharge hole 12 from being scattered outside the arc cover 200, and in particular, discharged from the T-shaped discharge hole 14 formed in the vicinity of the fixed contact 50 where the arc gas G is generated. A relatively large amount of arc gas G can be reliably prevented from scattering.

  In other words, since the arc gas is generated at the moment when the movable contact 40 leaves the fixed contact 50, a large amount of arc gas is generated in the vicinity of the fixed contact 50. Therefore, the arc gas G discharged from the T-shaped discharge hole 14 provided in the vicinity of the fixed contact 50 is the largest, and the discharge pressure is increased, so that the case 10 near the T-shaped discharge hole 14 and the arc cover 200 are joined together. It will be in a state where it is easily scattered outside. For this reason, in this embodiment, a flat surface 16 is provided between the T-shaped discharge hole 14 where the scattering of the arc gas G is the largest and the power supply side terminal 30, and the flat surface 16 and the contact surface 208 of the arc cover 200 face each other. By abutting in the state, scattering of the arc gas G can be reliably suppressed. Of course, the buffer piece 200e having the contact surface 208 may be provided on the opposite terminal portion 200c (the handle 70 side) of the arc cover 200. As a result, the abutting surface 208 abuts on a plane formed between the rectangular discharge hole 14 and the handle 70 in the case 10, and the arc gas G is in contact with the case 10 and the arc cover 200 (more specifically, the anti-terminal portion 200 c). It is possible to more effectively prevent leakage from the seam.

  Next, the circuit breaker 2 according to the second embodiment will be described. The second embodiment is characterized in that, when a large current is used, two cases 10 are connected in parallel to shunt the current, and a shielding plate 250 is provided between the two cases 10.

  FIG. 9A is a front view of the circuit breaker 2 according to the second embodiment, FIG. 9B is a side view of the circuit breaker 2, and FIG. It is the front view seen from the arrow TT direction of the same circuit breaker 2 of 9 (a).

  In addition, illustration and detailed description are abbreviate | omitted about the same member as what was demonstrated in 1st Embodiment.

  The shielding plate 250 is a plate member made of resin, and between the load-side terminals 20 and 20 and the power-side terminals 30 and 30 of the cases 10 and 10 in a state of being arranged in parallel, and from the cases 10 and 10. It arrange | positions so that it may protrude outside. The case piece 10a is formed with a shielding plate recess 19 that is recessed by one step from the outer surface of the case piece 10a for inserting the shielding plate 250. Therefore, the shielding plate 250 is inserted into the shielding plate recess 19 of the case piece 10a, and is sandwiched and engaged with the pair of case pieces 10a and 10a from both side surfaces. In the present embodiment, the holding plate 120 is not installed on the pair of case pieces 10a and 10a sandwiching the blocking plate 250. However, one magnet 100 is held by holding recesses 17 and 17 formed in both case pieces 10a and 10a.

  In other words, when the two cases 10 are connected in parallel, the shielding plate 250 shields between the load side terminals 20, 20 and the power source side terminals 30, 30 arranged side by side, and is electrically short-circuited with each other. In addition, when a cable (not shown) is fixed to the load side terminal 20 or the power supply side terminal 30, it is possible to avoid a risk that a cable, an operator's hand, or the like comes into contact with the terminal provided together.

  Moreover, when connecting the two cases 10 and 10 in parallel, it is preferable to use the arc cover 400 shown in FIG. 10A is a front view of the arc cover 400 according to the second embodiment, FIG. 10B is a right side view of the arc cover 400, and FIG. 10C is the arc cover. FIG. 4D is a bottom view of the arc cover 400, FIG. 4E is a plan view of the arc cover 400, and FIG. FIG. 10C is a cross-sectional view as viewed from the YY direction, and FIG. 10G is a cross-sectional view as viewed from the U-U direction in FIG. ) Is an enlarged view of a portion H in FIG.

  The arc cover 400 generally has a shape such that the arc covers 200 described in the first embodiment are connected in parallel.

  The arc cover 400 is provided with a blocking wall 410 at the approximate center inside. The blocking wall 410 divides the arc housing portion 402 into two spaces 402a and 402a. In addition, the blocking wall 410 slightly protrudes from the opening of the arc housing portion 402 (see FIG. 10H). As a result, the blocking wall 410 can enter the back of the gap 11A (see FIG. 9C) generated by the difference between the corners R of the two case pieces 10a and 10a arranged in parallel and the processing accuracy. . Therefore, the arc cover 400 can isolate the arc gas discharge holes 12 and 12 of the two cases 10 and 10 arranged in parallel by the blocking wall 410. That is, the arc gas G discharged from the arc gas discharge hole 12 of one case 10 and the arc gas G discharged from the arc gas discharge hole 12 of the other case 10 do not come into contact with each other. Can be prevented.

  Similarly to the arc cover 200, the arc cover 400 has a ceiling portion 400 a that faces the arc gas discharge hole 12 of the case 10, and stands between the arc discharge hole 12 and the power supply side terminal 30. A terminal portion 400b that isolates the terminal portion 400b, an opposite terminal portion 400c that faces the terminal portion 400b, and a pair of side portions 400d that correspond to the outer surface 126 of the case 10 (see FIG. 10).

  Further, a shielding plate relief portion 420 is formed at a position corresponding to the shielding plate 250 disposed between the pair of cases 10 and 10 in the approximate center of the terminal portion 400b. The shielding plate escape portion 420 is formed so as to reach a part of the space 402 from the buffer piece 400e. That is, the above-described blocking wall 410 is provided up to the end of the blocking plate relief 420. Due to the presence of the shielding plate relief portion 420, the arc cover 400 escapes the shielding plate 250 protruding outward from the case pieces 10a and 10a arranged in parallel, and simultaneously engages with the cases 10 and 10 arranged in parallel. Can be combined.

  In this embodiment, the shielding wall 410 is slightly protruded from the opening of the arc housing portion 402 in order to isolate the two spaces 402, 402 of the arc housing portion 402. It is not limited to this. For example, the end portion (case side end portion) of the shielding wall 410 may have a planar shape wider than the gap 11A. By doing so, when the arc cover 400 is engaged with the case 10, the plane of the end of the shielding wall 410 abuts against the outer surfaces of the cases 10 and 10, thereby isolating the spaces 402 and 402. Can do.

  In the present embodiment, one or two cases 10 are connected in parallel. However, the number of cases 10 is preferably changed according to the voltage or current applied to the circuit breaker. Needless to say, the case 10 may be connected in parallel. In that case, it is preferable that the shielding wall 410 of the arc cover 400 is provided according to the number of cases 10 connected in parallel to shield the arc gas discharge holes 12 of the individual cases 10.

  Further, according to the present invention, the load terminal 20, the pair of terminals (the power source terminal 30 and the movable contact 40), and the fixed contact 50 are built in the case 10, and the arc gas that communicates with the outside in the vicinity of the fixed contact of the case 10. A discharge hole 12 is provided. An arc cover 200 is assembled outside the arc gas discharge hole 12 so as to surround the arc gas discharge hole 12. Therefore, the arc gas G generated when the movable contact 40 moves away from the fixed contact 50 is taken into the arc accommodating portion 202 (internal space) of the arc cover 200 through the arc gas discharge hole 12. It can be prevented from splashing outside.

  The case 10 is provided with a case side engaging portion (referred to as an engaging convex portion 124), and the arc cover 200 is formed with a cover side engaging portion (referred to as an engaging concave portion 202). Therefore, the arc cover 200 can be attached to and detached from the case 10 by the engagement convex portion 124 and the engagement concave portion 202 engaging.

  Moreover, since the engagement convex part 124 and the engagement concave part 202 are attached and detached by a snap fit structure, the arc cover 200 can be easily detached from the case 10.

  Further, the case 10 is provided with a flat surface 16 between the arc gas discharge hole 12 and the power supply side terminal 30, and the buffer piece 200 e of the arc cover 200 is in contact with the flat surface 16 of the case 10 in a surface state. Is formed. Therefore, when the arc cover 200 is engaged with the case 10, the contact surface 208 of the arc cover 200 is in close contact with the flat surface 16 of the case 10 in a surface state, so that the arc gas G that is often generated in the vicinity of the fixed contact 50. Can be cut off efficiently.

  Further, the case 10 is formed with a holding portion (holding concave portion 17) for holding the magnet 100 in the vicinity of the fixed contact 50, and the arc gas is discharged from the arc gas discharge hole 12 by the Lorentz force of the magnet 100, and the arc cover 200. It is comprised so that it may be taken in into the arc accommodating part. Therefore, the arc gas is reliably discharged from the arc gas discharge hole 12.

  A plurality of cases 10 are provided in parallel, and at least a fixed contact 50 and a movable contact 40 are accommodated in each case 10, 10. Therefore, a large current can be cut off by diverting the current to each of the plurality of cases 10 and 10.

  In addition, a case abutting surface 11 is provided on the side surface of the plurality of cases 10 and 10, and the plurality of cases 10 and 10 are engaged with each other by the case abutting surface 11. Can be connected.

  Further, since the magnet 100 is held between the holding recesses of the cases 10 and 10 connected in parallel, the arc gas is discharged by the Lorentz force of the magnet even when the cases 10 and 10 are connected in parallel. The holes 12 can be discharged.

  The case 10 includes at least a case piece 10a having an internal space for accommodating the movable contact 40 and the fixed contact 50, and a holding plate 120 that engages with an outer surface of the case piece 10a. A recess (holding recess 17 or recess 122) for accommodating the magnet 100 is formed in one of the case piece 10a or the holding plate 120. Therefore, the magnet 100 is accommodated in the holding recess 17 of the case piece 10 a or the recess 122 of the holding plate 120.

  Moreover, since the arc cover 400 is configured to be engaged so as to simultaneously surround the arc gas discharge holes 12 of the plurality of cases 10 and 10 connected in parallel, the plurality of cases 10 and 10 are connected in parallel. Even in this case, it is possible to reliably prevent the arc gas discharged from the arc gas discharge hole 12 from being scattered outside the arc cover 400.

  In addition, when a plurality of cases 10 and 10 are connected in parallel, a shielding plate 250 that shields each pair of terminals (the load side terminal 20 and the power source side terminal 30) is further provided. Further, since the case 10 is provided with the shielding plate recess 19 for holding the shielding plate 250, when a plurality of cases 10 are connected in parallel, the shielding plate 250 is inserted between the cases 10 and 10. Thus, a short circuit between the terminals 20, 20 and 30, 30 can be prevented.

  Further, the arc cover 400 is provided with a blocking wall 410 that blocks the arc gas discharge holes 12 and 12 of each case 10 when a plurality of cases 10 and 10 are connected in parallel. Therefore, in the arc cover 400, the arc gas discharged from the arc gas discharge hole 12 of one case 10 connected in parallel and the arc gas discharged from the arc gas discharge hole 12 of the other case 10 come into contact with each other by the blocking wall 410. Can be prevented.

  The arc cover 400 is a substantially hexahedron member that is partially open and has an internal space (arc accommodating portion 402). The internal space of the arc cover 400 is connected to the arc gas discharge hole 12 in the case 10 through the opening. It is provided so that it may communicate with. Therefore, the arc gas G discharged from the arc gas discharge hole 12 can be taken into the arc cover 200.

  In addition, the arc cover 400 is erected with respect to the ceiling part 400 a that forms the arc accommodating part 402 and faces the arc gas discharge hole 12 in the case 10, and the ceiling part 400 e, and is connected to the arc gas discharge hole 12 and the power supply side terminal 30. It further includes a terminal portion 400b disposed therebetween, a non-terminal portion 400c facing the terminal portion 400b, and a pair of side portions 200d corresponding to the outer surface 126 of the case 10. The terminal portion 200 b is provided at a position that isolates the arc gas discharge hole 12 from the power supply side terminal 30. Therefore, the terminal portion 200b of the arc cover 400 can shield the arc gas discharge hole 12 and the power supply side terminal 30 from leaking out of the gap between the case 10 and the arc cover 400.

  Further, a buffer piece 200e protruding in the direction of the opening surface is provided at the opening edge of the terminal portion 200b, and the arc gas discharge hole 12 and the power supply side terminal 30 in the case 10 are formed on the surface of the buffer piece 200e facing the case 10. A contact surface 208 is further provided at a position that contacts between the contact surfaces 208. Therefore, the arc cover 400 can more efficiently prevent the arc gas G from leaking from the gap between the case 10 and the arc cover 400.

  The pair of side portions 400d of the arc cover 400 is provided with a cover side extension portion 404 that extends from the opening end surface of the arc housing portion 202 to the outer surface 126 side of the case 10 as it is. The outer surface 126 of the case 10 is engaged. Therefore, it is possible to efficiently prevent the arc gas G from leaking from the outer surface 126 of the case 10.

  Note that the circuit breaker of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

  The present invention can be widely used in the field of circuit breakers that interrupt current.

It is a figure which shows the internal structure of the circuit breaker 1 which shows the state (cutting | disconnection state) which the movable contact and the fixed contact have left | separated based on 1st Embodiment. It is a figure which shows the internal structure of the circuit breaker 1 which shows the state (energization state) in which the said movable contact is contacting the fixed contact. It is the front view of case 10 which abbreviate | omitted the holding plate seen from the arc gas discharge hole direction. It is explanatory drawing explaining the discharge method of arc gas. It is the exploded view of case 10 which abbreviate | omitted the arc cover seen from the arc gas discharge hole direction. (A) It is a front view of the arc cover 200 which concerns on 1st Embodiment, (b) It is a right view of the arc cover 200, (c) It is a left view of the arc cover 200, (d) It is a bottom view of the arc cover 200, (e) It is a top view of the arc cover 200. (A) It is sectional drawing seen from the arrow PP direction of FIG.6 (c), (b) It is sectional drawing seen from the arrow QQ direction of FIG.6 (c). It is a front view of the circuit breaker 1 just before the arc cover 200 is assembled | attached, (b) It is a side view of 1 to the circuit breaker. (A) is a front view of the circuit breaker 2 according to the second embodiment, (b) is a side view of the circuit breaker 2, and (c) is an arrow in FIG. 9 (a). It is the front view seen from the visual TT direction. (A) It is a front view of the arc cover 400 which concerns on 2nd Embodiment, (b) It is a right view of the arc cover 400, (c) It is a left view of the arc cover 400, (d) FIG. 10 is a bottom view of the arc cover 400, (e) a plan view of the arc cover 400, (f) a cross-sectional view seen from the YY direction of FIG. 10 (c), and (g) FIG. It is sectional drawing seen from the arrow UU direction of (c), (h) It is an enlarged view of the H section of the same figure (g). It is a side view used as the partial cross section of the conventional circuit breaker. (A) In the same circuit breaker, it is sectional drawing which expanded the vicinity of the discharge port which shows the state which arc gas has not generate | occur | produced, (b) The sectional view which expanded the vicinity of the discharge port which shows the state which discharges the arc gas It is. (A) It is a disassembled perspective view of the other conventional circuit breaker, (b) It is a perspective view of the terminal cover of the circuit breaker. It is a side view used as a partial section of other conventional circuit breakers.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit breaker 10 Case 10a Case piece 12 Arc gas discharge hole 12a Arc gas discharge groove 20 Load side terminal 30 Power supply side terminal 40 Movable contact 50 Fixed contact 60 Frame 70 Handle 80 Movable link 90 Cable 100 Magnet 200 Arc cover 250 Shield plate

Claims (18)

Case and
A pair of terminals held in the case;
A fixed contact disposed in the middle of a load current path connecting the pair of terminals;
A movable contact that is arranged in the middle of the load current path and switches between energization and interruption of the load current in contact with and away from the fixed contact;
An arc gas discharge hole that is formed near the fixed contact in the case and discharges arc gas generated when the movable contact contacts or separates from the fixed contact to the outside of the case;
An arc cover provided so as to surround the arc gas discharge hole outside the case;
A circuit breaker comprising: The case is formed with a case side engaging portion,
The arc cover is formed with a cover side engaging portion,
When the cover side engaging portion engages with the case side engaging portion, the arc cover is detachably attached to the case.
The circuit breaker according to claim 1. The cover side engaging portion and the case side engaging portion are engaged by snap fit,
The circuit breaker according to claim 2. The arc cover is provided with a surface around the arc gas discharge hole in the case, and a contact surface that contacts the surface in a surface state.
The circuit breaker of any one of Claim 1 or 3. The contact surface is disposed at least between the terminal and the arc gas discharge hole,
The circuit breaker according to claim 4. A holding portion for holding a magnet is formed in the vicinity of the fixed contact in the case, and the magnet is held in the holding portion,
The arc gas is discharged from the arc gas discharge hole by Lorentz force generated by the magnet,
The circuit breaker according to any one of claims 1 to 5. The case includes at least a case piece that forms an internal space in which the fixed contact and the movable contact are accommodated, and a holding plate that is mounted on an outer wall of the case piece,
At least one of the case piece and the holding plate is formed with a recess serving as the holding portion for holding the magnet,
The magnet is sandwiched between the case piece and the holding plate while being accommodated in the recess.
The circuit breaker according to claim 6. The case side engaging portion is formed on the holding plate side of the case,
The circuit breaker according to claim 7. A plurality of cases,
Each of the cases contains at least the fixed contact and the movable contact,
The circuit breaker according to any one of claims 1 to 8. Each of the plurality of cases includes a case contact surface that engages with the other case.
One of the cases is engaged with the other case by the case contact surface, so that the plurality of cases are connected in parallel.
The circuit breaker according to claim 9. The plurality of cases are connected to each other in parallel with the magnet sandwiched therebetween, and the arc gas is discharged from the arc gas discharge hole by Lorentz force generated by the magnet. And
The circuit breaker according to claim 9 or 10. A single arc cover simultaneously surrounds the arc discharge holes of a plurality of the cases connected in parallel.
The circuit breaker according to any one of claims 9 to 11. A shielding plate that shields the pair of terminals of one case and the pair of terminals of the other case;
The arc cover is provided with a shield plate escape portion into which the shield plate is inserted,
The circuit breaker according to any one of claims 9 to 12. The arc cover has a blocking wall inside,
The blocking wall is located between the arc gas discharge hole of one case connected in parallel and the arc gas discharge hole of the other case,
The circuit shield according to any one of claims 9 to 13. The arc cover is a substantially hexahedral member having an internal space with a part opened,
The internal space of the arc cover is provided to communicate with the arc gas discharge hole in the case through the opening.
The circuit breaker according to any one of claims 1 to 14. The arc cover includes a ceiling portion that faces the arc gas discharge hole in the case, a terminal portion that is erected with respect to the ceiling portion and disposed between the arc gas discharge hole and the terminal, and the terminal portion. It further comprises an opposing anti-terminal portion and a pair of side portions corresponding to the outer side surface of the case,
The circuit breaker according to claim 15. The opening edge of the terminal part is provided with a buffer piece protruding in the opening surface direction,
The surface of the buffer piece facing the case is further provided with a contact surface at a position that contacts the arc gas discharge hole and the terminal in the case.
The circuit breaker according to claim 16. The pair of side portions of the arc cover is provided with a cover side extension portion that extends as it is from the opening end surface of the internal space to the outer surface side of the case,
The cover side extension portion is engaged with an outer surface of the case,
The circuit breaker according to claim 16 or 17.

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